We received 20cm of snow in the past 24hrs. The storm slab is thick enough to produce large avalanches. Natural avalanches from steep paths have been running to valley bottom. Spread out and put in the higher track up Connaught to minimize exposure.
Weather Forecast
Another 5-10cm are expected today with strong SW winds. A strong pacific front will move into the region on Tuesday bringing another 10-20cm, high to extreme SW winds at ridgetop and freezing levels rising to 1500m. On Wednesday, with the passage of the front unsettled conditions will continue with light to moderate precipitation and strong W winds
Snowpack Summary
A 60cm storm slab is becoming increasingly cohesive. This overlies the Nov28 layer which will be most reactive where it overlies a suncrust on S slopes or where surface hoar was buried; sheltered areas at treeline. Moderate-strong S'ly winds have formed soft slabs and loaded lee slopes. The Nov 6 crust may become reactive with increasing load.
Avalanche Summary
Natural avalanche activity has been occurring from steep complex terrain during periods of intense wind and snowfall. Most are size 2-2.5, and several paths have run repeatedly, some running to the end of their runouts. There have been reports of natural avalanches from the Cheops north paths.
Problems
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.